Since we both had a morning off work, Titus Pullo and I played our first game of 40k this year with some WIP armies on WIP terrain... don't worry, we took pics! :D
We were using the standard Imperial SM codex, and the Forgeworld Imperial Armour
Siege of Vraks lists for the renegade army troopers.
Traitor ForcesHQ
EC Captain Argento
Elite
Brother Faustus, Dreadnought armed with a missile launcher and assault ("experimental auto-") cannon
Troops
Tactical Squad Hera, 5 Marines including Plasma gunner and veteran sergeant
Tactical Squad Aphrodite, 5 Marines including Plasma gunner and veteran sergeant
2nd Platoon XIIth Company of the Traitor 5th Rgt
HQ unit inc Vox caster and plasma gunner
2 Squads of 10 men inc Mortar and Heavy Stubber
Loyalist ForcesHQ
SW Captain Svenjursson
Elite
Wolf Brother Fisk, Dreadnought armed with twin linked lascannon and CCW
Troops
Hunter Squad Ragnarok, 10 Marines with close combat weapons and bolt pistols
Scout Squad Hlokk, 5 Scouts with 2 Snipers
Fast Attack
Assault Squad Bryndr, 5 Marines with close combat weapons and jump packs
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The two forces deployed on either side of the temporary bridge over the stagnant river, being the only remaining crossing in the capital city. The Traitors opted to take cover in the higher ruins, where their mortar fire would be able to attack the more exposed Loyalists who had quick-marched through the rubble on the other side.

Dreadnought Faustus intended to advance through a narrow alley to cut off Loyalist troops from the bridge, but stumbled and became immobilised between the buttresses at the opening! This still gave him a good field of fire, but without Techmarine support he was a sitting duck...
Traitor army units advanced carefully through the wreckage left by the orbital bombardment, and soon caught sight of their foes across the river.

An opening barrage from the mortars hidden in the tall ruins scored a direct hit on the advancing Hunters, but they shrugged off the blast with their superior armour and continued to make for the objective. Long range fire between the two Dreadnoughts was exchanged but no damage was taken.

From their vantage point atop the tallest ruin on the eastern bank, Scout snipers took out a lone army trooper. The time for the renegades to test their devotion to their dark masters was here - they cared little for the concerns of their own mortality, and continued to hurry out into the wrecked streets!
Assault squad Bryndr leaped over the foul waters to the island in the north of the battlefield, only to be met by a withering hail of plasma and explosive bolts from the traitors of Hera squad.

While the rest of the Loyalists tried to close range and seize the bridge, Bryndr continued their crossing to the far bank, and flung themselve into a vicious assault with their attackers.

The combat was short and bloody, and left only the squads' veteran sergeants grappling over the fallen bodies of their brethren.

Under covering fire from the snipers, squad Ragnarok made it to the bridge only to see the purple-armoured killers of Aphrodite towering over them in the ruins beyond - a blaze of bolts tore through their ranks but casualties were mercifully few, given the grave error in tactics!
Charging from cover, the first Traitor army squad shrugged off more sniper hits and let loose with their rifles upon the Space Wolves crossing the bridge. Still trapped in the alleyway, Faustus opened up with all weapons on Fisk in sheer frustration, and managed to sever something important in his rival's inner workings. The Loyalist war machine ground to a halt at the very edge of the precipice, and after recovering from the shock of the impact slowly brought his own weapons to bear...

The surviving Sergeant Hera dispatched his Loyalist foe and dashed to join the fray once more, seeking to join up with the surviving renegades who were still dodging sniper shots from the buildings on the far bank.
Mortar shells landing in the stagnant waters around them, the first Hunters reached the traitor-held western ruins only to be massacred by the combined firepower of squad Aphrodite and the heavy stubber brought in by the advancing renegade troopers.

As the sixth of their number fell to a deadly shot from an unseen sniper, the renegades decided they had had enough of the Emperor's vengeance and fled for the safety of their own lines once more, despite their regimental commander's bellowed threats and the presence of the hallowed Chaos standard! Cursing their cowardice, the hulking officer brought his command squad out into the open, flanked by the regal armoured form of Captain Argento.

More wildly inaccurate shots tore up the ruins around the two immobilised Dreadnoughts as each tried to wreck the other, or bury him amidst the rubble of the unsound battlefield. A lucky flurry of hits from Faustus' experimental new assault cannon knocked Fisk's sensors awry, and silenced his weapons for a time. With the Space Wolves holding the objective, it was now or never if the Traitors still sought victory!
Sergeant Hera continued his desperate bloodthirsty charge for the bridge, but took the brunt of the decimated Ragnarok's defensive fire and fell like a husk of charred meat as the meltagun dealt its fiery retribution.

Hoping to lead the surviving Hunters, Captain Svenjursson sprang from the bridge to his brothers' aid, but more bolter fire reduced the squad to just the meltagun specialist. Before he could bring his weapon to bear, the traitor Captain Argento was upon them, his power sword flashing left and right as if guided by Slaanesh's very will! Svenjursson roared and rushed to counterattack, and an almost palpable sense of expectation settled over the surviving armies as they watched the mighty struggle unfold...

Both landing deadly blows upon one another, the two captains struggled bodily to claim the bridge and ultimate victory. Arcs of energy played from their blades as they met and parried, until finally Svenjurrson's strength failed him and the wounded Argento landed a killing blow. As he tossed his fallen opponent into the foul waters below, he realised that he was in full sight of the Dreadnought Fisk and his deadly lascannons...
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Although both sides held equal claim to the objective at the end of the game (don't fancy Argento's chances against the Dreadnought much!) the Traitors achieved a clear victory in points. The massacre of Hunter squad Ragnarok and the loss of the jump pack troops early on meant that the well defended ruins were the perfect place to play a game of attrition, and play it well. It seems these particular Traitors had the blessing of their dark masters this day!